diff mbox series

[net-next,v2,03/10] bnxt_en: Allow some TX packets to be unprocessed in NAPI

Message ID 20240628193006.225906-4-michael.chan@broadcom.com (mailing list archive)
State Accepted
Commit ba0155f1e9fca8e5c59c840cf5451101b8360fe6
Delegated to: Netdev Maintainers
Headers show
Series bnxt_en: PTP updates for net-next | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 839 this patch: 839
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/build_clang success Errors and warnings before: 846 this patch: 846
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 848 this patch: 848
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 74 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 2 this patch: 2
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-06-29--06-00 (tests: 665)

Commit Message

Michael Chan June 28, 2024, 7:29 p.m. UTC 
The driver's current logic will always free all the TX SKBs up to
txr->tx_hw_cons within NAPI.  In the next patches, we'll be adding
logic to handle TX timestamp completion and we may need to hold
some remaining TX SKBs if we don't have the timestamp completions
yet.

Modify __bnxt_poll_work_done() to clear each event bit separately to
allow bnapi->tx_int() to decide whether to clear BNXT_TX_CMP_EVENT or
not.  bnapi->tx_int() will not clear BNXT_TX_CMP_EVENT if some TX
SKBs are held waiting for TX timestamps.  Note that legacy chips will
never hold any SKBs this way.  The SKB is always deferred to the PTP
worker slow path to retrieve the timestamp from firmware.  On the new
P7 chips, the timestamp is returned by the hardware directly and we
can retrieve it directly from NAPI.

Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index af064dcc6142..9dbf2967df1c 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -770,7 +770,8 @@  static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	return NETDEV_TX_OK;
 }
 
-static void __bnxt_tx_int(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
+/* Returns true if some remaining TX packets not processed. */
+static bool __bnxt_tx_int(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
 			  int budget)
 {
 	struct netdev_queue *txq = netdev_get_tx_queue(bp->dev, txr->txq_index);
@@ -793,7 +794,7 @@  static void __bnxt_tx_int(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
 
 		if (unlikely(!skb)) {
 			bnxt_sched_reset_txr(bp, txr, cons);
-			return;
+			return false;
 		}
 
 		tx_pkts++;
@@ -842,18 +843,22 @@  static void __bnxt_tx_int(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
 	__netif_txq_completed_wake(txq, tx_pkts, tx_bytes,
 				   bnxt_tx_avail(bp, txr), bp->tx_wake_thresh,
 				   READ_ONCE(txr->dev_state) == BNXT_DEV_STATE_CLOSING);
+
+	return false;
 }
 
 static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int budget)
 {
 	struct bnxt_tx_ring_info *txr;
+	bool more = false;
 	int i;
 
 	bnxt_for_each_napi_tx(i, bnapi, txr) {
 		if (txr->tx_hw_cons != RING_TX(bp, txr->tx_cons))
-			__bnxt_tx_int(bp, txr, budget);
+			more |= __bnxt_tx_int(bp, txr, budget);
 	}
-	bnapi->events &= ~BNXT_TX_CMP_EVENT;
+	if (!more)
+		bnapi->events &= ~BNXT_TX_CMP_EVENT;
 }
 
 static struct page *__bnxt_alloc_rx_page(struct bnxt *bp, dma_addr_t *mapping,
@@ -2950,8 +2955,10 @@  static int __bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 		}
 	}
 
-	if (event & BNXT_REDIRECT_EVENT)
+	if (event & BNXT_REDIRECT_EVENT) {
 		xdp_do_flush();
+		event &= ~BNXT_REDIRECT_EVENT;
+	}
 
 	if (event & BNXT_TX_EVENT) {
 		struct bnxt_tx_ring_info *txr = bnapi->tx_ring[0];
@@ -2961,6 +2968,7 @@  static int __bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 		wmb();
 
 		bnxt_db_write_relaxed(bp, &txr->tx_db, prod);
+		event &= ~BNXT_TX_EVENT;
 	}
 
 	cpr->cp_raw_cons = raw_cons;
@@ -2978,13 +2986,14 @@  static void __bnxt_poll_work_done(struct bnxt *bp, struct bnxt_napi *bnapi,
 		struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
 
 		bnxt_db_write(bp, &rxr->rx_db, rxr->rx_prod);
+		bnapi->events &= ~BNXT_RX_EVENT;
 	}
 	if (bnapi->events & BNXT_AGG_EVENT) {
 		struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
 
 		bnxt_db_write(bp, &rxr->rx_agg_db, rxr->rx_agg_prod);
+		bnapi->events &= ~BNXT_AGG_EVENT;
 	}
-	bnapi->events &= BNXT_TX_CMP_EVENT;
 }
 
 static int bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,